1. Field of the Invention
This invention relates to spacecraft and in particular to a method of assembling a structure in space and subsequently landing the space structure on an extraterrestrial body.
2. Description of the Prior Art
Many scenarios involving manned missions to the moon and other planets require landing a structure that can support human life. One issue with such extraterrestrial structures is the volume available for the inhabitants. The space within such a structure should accommodate living quarters, environmental support, storage, experimentation and instrumentation housing, to name just a few.
While large rigid structures may provide acceptable volume, these structures are expensive to deploy in space. Also, there is a practical limit as to the size of a rigid structure that can be launched into space based upon the size of the launch vehicle.
Another option is to launch a number of smaller rigid shelled modules to an extraterrestrial mass and assemble those modules into a larger structure on the surface of the celestial object. Several drawbacks to this approach are that it is expensive, time consuming, increases the likelihood of failure, and it most likely will require humans to participate in the construction of the shelter. This can expose the workers to substantial risk.
The environments of known extraterrestrial objects to date are inimical to human life. People must rely upon protective enclosures such as space suits to be ambulatory on the surface of the object. This extends to workers who would be assembling individual modules into a larger structure. It follows that if a person's protective space suit is damaged during the construction process, then the individual may suffer injury or death as a result.
One way to increase the volume of a deployed spacecraft and at the same time reduce the cost of deployment is to use inflatable modules. Inflatable spacecraft are known in the art as evidenced by U.S. Pat. No. 6,231,010 to Schneider, et al., and U.S. Pat. No. 6,547,189 to Raboin, et al. This type of craft is novel in that the shell is made of a generally pliable and flexible material as opposed to the solid shell of more traditional spacecraft.
The flexible shell allows the spacecraft to exist in one of two states. The first state is the pre-deployed state where the craft can be compressed to fit within the volume of a launch fairing. After launch and when the craft is released from the fairing, the vehicle can assume the second state or the deployed state. In this state, the craft is inflated to expand to many times the size of the pre-deployed volume.
Such modules have been proposed as the vehicle of choice for lunar and Mars manned missions. In these scenarios a module, or modules, would be landed on the surface of a planet. While this addresses the volume issue, it does not reduce the risk factor. In the case of multiple modules, human intervention would still be required to assemble the final structure and this process still exposes people to danger. This also exposes the project the chance of a failure to complete the construction.
What is needed is a method for deploying a large volume structure to an extraterrestrial object where the need to engage in construction on the surface of the object is substantially reduced if not eliminated. This includes the need for a more economical approach, a shorter term of construction, and a greater chance of completing the construction.